Frequently Asked Questions (FAQ)

Q: Can you tell me how aquatic treatment areas are decided on each year?

A: Each year, MLIRD commissions experienced, aquatic professionals to conduct survey work on Moses Lake. The results from those efforts, combined with community input, leads to an aquatic treatment strategy for that given year. A multi-phased approach is preferred, but that is dependent on budget considerations.

Q: When does the lake elevation rise for summer and when is lake elevation lowered for winter?

A: Deliberate elevation rise begins in late March and Dam gates close no later than the first Monday in April to fill the lake. Elevation is lowered for winter starting on the first Monday in November. The filling and draining process usually takes around three weeks depending on weather. Moses Lake typically has a surface elevation of 1046.70 feet during the summer and drops to an elevation of 1041.30 feet during winter.

Q: I'm new to the area, is there any nautical or bathymetry charts available for Moses Lake?

A: There are many sources available on the Internet. Here's one link that might help but keep in mind that MLIRD bears no responsibility for data accuracy. GPS Nautical Charts or WA Lakes

Q: Can I dispose of tree leaves and lawn clippings by dumping them into the lake?

A: This should ALWAYS be avoided. One of the major contributors to blue-green algae is phosphorus & nitrogen, and one of the leading nutrient sources can be yard debris such as lawn clippings getting into the lake. Homeowners, especially lakefront property owners, should ensure they use only as much fertilizer as needed to keep their lawn healthy and then insist on phosphorus-free fertilizer products to avoid additional lake water nutrient loading through run-off where possible.


Yard care near lakes     Yard debris & water quality     Watersheds, lawn care & lake water quality    

Phosphorus & runoff concerns     Lake water, Watersheds & Algae  

Q: Has Moses Lake been tested for Blue Green Algae?

A: The Grant County Health District has done Blue Green Algae testing on area waters. 

     See this page for more info on their findings: Blue Green Algae

Click HERE for Blue-Green Algae Facts

More Reading:

Dept of Ecology on Algae   WA State Toxic Algae   University of Oregon on Blue-Green Algae   Moses Lake Phosphorus Study  

Poisonous Algae Blooms      Wisconsin Blue-Green Video      Wisconsin Blue-Green FAQ       USGS

Q: How do I get my company on the MLIRD Small Works Roster or Small Purchase Roster?

A: These Rosters may be used to solicit and secure telephone and/or written quotations for maintenance, improvement projects and in some cases materials, supplies or equipment purchases. All vendors, contractors, suppliers or other parties wanting to be included in these Roster processes must obtain an Application from the District. A completed Application must then be returned to the District to be included on the respective Rosters. Applications may be obtained via telephone request (509) 765-8716, email request at, by written request sent to P O Box 98, Moses Lake WA 98837 or

Q: I'd like to modify and add to my dock.  Any direction on that?

A: The scope of your project will determine what permitting requirements are needed. The resource links below will help satisfy your needs.  Also, the Grant County Planning Dept may help at (509) 754-2011.

Grant County Planning     JARPA Resources     City of ML Planning     City of ML Environmental Checklist     SEPA Checklist    

Q: What all is involved for a new homeowner to establish pumping service from the lake for irrigation purposes? Am assuming JARPA, SEPA, Shoreline Permit, and Construction Permit. Is that it?

A: It depends on if there needs to be any excavation to bury the waterline or if it will just set on top. If there is any excavation into the shore of the lake an Army Corps permit is needed. Otherwise what you have listed plus a WDFW permit is it.

Q: When will the North Dam project be completed?

A: The North Dam replacement project began on Monday, 10/27/2014 and is expected to conclude in March 2015.   The road passing through the area is expected to be out of commission at the construction site for much of the project duration however for the first week or two, contractors attempted to accommodate thru-traffic to the extent possible.  Following that, no opportunity for thru-traffic exists so please plan accordingly.  Contractors will attempt to minimize restrictions to the extent possible and this project shouldn't impact access to the south Bureau dam from the Potato Hill Road entrance.  As more information is available, we will post updates.